Heart II

Question 1

what are the coronary arteries known as?

Answer 1

-they’re known as being the first branches of the aorta

Question 2

how many branches does the right coronary artery divide into?

Answer 2

-two branches

Question 3

right coronary artery components

Answer 3

• marginal branch

- posterior interventricular(PCA) branch

Question 4

marginal branch of right coronary artery

Answer 4

-supplies myocardium of the inferior wall of both ventricles

Question 5

posterior interventricular branch of right coronary artery

Answer 5

-travels in sulcus on posterior side to supply posterior wall of both ventricles

Question 6

how many branches does the left coronary artery divide into?

Answer 6

-two branches

Question 7

left coronary artery components

Answer 7

• anterior interventricular branch

- circumflex branch

Question 8

anterior interventricular branch of left coronary artery

Answer 8

• aka left anterior descending(LAD) or widowmaker

- supplies interventricular septum and anterior wall of both ventricles

Question 9

circumflex branch of left coronary artery

Answer 9

-supplies left atrium and posterior-lateral left ventricle

Question 10

venous drainage

Answer 10

-three main veins (great, small, and middle) drain blood into coronary sinus which empties into the right atrium

Question 11

electrical conduction system of the heart types

Answer 11

• primary (intrinsic) regulating system

- secondary (extrinsic) regulating system

Question 12

primary (intrinsic) regulating system function

Answer 12

• stimulates cardiac muscle fibers to contract w/o need for any direct stimulus from nervous system
• composed of specialized muscle tissue that generates and distributes required electrical impulses throughout heart

Question 13

secondary (extrinsic) regulating system function

Answer 13

• alters heart rates through ANS control to meet immediate needs of the body
• ex: when exercising

Question 14

intrinsic conduction system components

Answer 14

• sinoatrial(SA) node
• atrioventricular node
• atrioventricular bundle of His
• purkinje fibers

Question 15

sinoatrial(SA) node location

Answer 15

• aka ‘pacemaker’ of the heart

- collection of specialized “conducting cells” located in wall of right atrium

Question 16

sinoatrial(SA) node function

Answer 16

• initiates heartbeat

- sends message to left atrium

Question 17

atrioventricular node

Answer 17

• sends message to the bundle of His

- receives message from SA node located in right atrium

Question 18

atrioventricular bundle of His

Answer 18

• tract located in IV septum

- transmits message to purkinje fibers

Question 19

what is a tract?

Answer 19

-collection of conduction fiber

Question 20

purkinje fibers

Answer 20

• located in walls of the ventricles
• conducts impulse to myocardium
• results in ventricular contraction

Question 21

extrinsic control system

Answer 21

• controlled through ANS pathways

- alters heart rate to meet needs of body

Question 22

extrinsic control system components

Answer 22

• sympathetic stimulation

- parasympathetic stimulation

Question 23

sympathetic stimulation

Answer 23

• release of norepinephrine
• acts on SA node
• increases heart rate and strength of contraction

Question 24

parasympathetic stimulation

Answer 24

• inhibitory (vagus CN X)
• releases acetylcholine
• decreases heart rate

Question 25

cardiac cycle

Answer 25

- refers to one complete heartbeat - SA node initiates each cycle - occurs 70 times per minute

Question 26

as the atria contacts, what does this do in the heart?

Answer 26

-it forces blood into both ventricles

Question 27

systole in cardiac cycle

Answer 27

- ventricles contract** | - AV valves close and through SLV blood is ejected from the heart

Question 28

diastole in cardiac cycle

Answer 28

- ventricles relax - AV valves open and SLV valves close - blood has filled atria which are awaiting the signal from SA node to begin next cardiac cycle

Question 29

which occurs first, systole or diastole?

Answer 29

-systole, then diastole

Question 30

what occurs during an EKG?

Answer 30

- impulse transmission through conduction system generates electrical currents that may be detected on body's surface - each portion of cardiac cycle produces different electrical impulses which can be recorded on a graph as deflection waves

Question 31

"lubb-dubb" heart sounds

Answer 31

-sounds made by vibrations as the valves close

Question 32

auscultation

Answer 32

- act of listening to sounds within the body | - usually performed with the use of a stethoscope

Question 33

first heart sound

Answer 33

- "lubb" | - closure of AV values (ventricular contraction)

Question 34

second heart sound

Answer 34

- "dubb" | - closure of semilunar valve (ventricular relaxation)

Question 35

where is it best to listen to heart sounds?

Answer 35

-adjacent to the anatomical location of the valve(auscultatory areas)

Question 36

auscultatory areas components

Answer 36

- aortic area - pulmonic area - tricuspid area - bicuspid area

Question 37

aortic area

Answer 37

- aortic semilunar valve | - 2nd intercostal space, right side

Question 38

pulmonic area

Answer 38

- pulmonic semilunar valve | - 2nd intercostal space, left side

Question 39

tricuspid area

Answer 39

- right AV valve - 5th intercostal space - to the right of the sternum

Question 40

bicuspid area

Answer 40

- left AV valve - 5th intercostal space - to the left ot the sternum, near apex of heart